// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_KEYBOARD_KEYBOARD_CONTROLLER_H_
#define UI_KEYBOARD_KEYBOARD_CONTROLLER_H_

#include "base/event_types.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/observer_list.h"
#include "ui/aura/window_observer.h"
#include "ui/base/ime/input_method_observer.h"
#include "ui/base/ime/text_input_type.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/keyboard/keyboard_export.h"

namespace aura {
class Window;
}
namespace ui {
class InputMethod;
class TextInputClient;
}

namespace keyboard {

class CallbackAnimationObserver;
class KeyboardControllerObserver;
class KeyboardUI;

// Animation distance.
const int kAnimationDistance = 30;

enum KeyboardMode {
    // Invalid mode.
    NONE,
    // Full width virtual keyboard. The virtual keyboard window has the same width
    // as the display.
    FULL_WIDTH,
    // Floating virtual keyboard. The virtual keyboard window has customizable
    // width and is draggable.
    FLOATING,
};

// Provides control of the virtual keyboard, including providing a container
// and controlling visibility.
class KEYBOARD_EXPORT KeyboardController : public ui::InputMethodObserver,
                                           public aura::WindowObserver {
public:
    // Different ways to hide the keyboard.
    enum HideReason {
        // System initiated.
        HIDE_REASON_AUTOMATIC,
        // User initiated.
        HIDE_REASON_MANUAL,
    };

    // Takes ownership of |ui|.
    explicit KeyboardController(KeyboardUI* ui);
    ~KeyboardController() override;

    // Returns the container for the keyboard, which is owned by
    // KeyboardController.
    aura::Window* GetContainerWindow();

    // Whether the container window for the keyboard has been initialized.
    bool keyboard_container_initialized() const { return container_; }

    // Reloads the content of the keyboard. No-op if the keyboard content is not
    // loaded yet.
    void Reload();

    // Hides virtual keyboard and notifies observer bounds change.
    // This function should be called with a delay to avoid layout flicker
    // when the focus of input field quickly change. |automatic| is true when the
    // call is made by the system rather than initiated by the user.
    void HideKeyboard(HideReason reason);

    // Notifies the keyboard observer for keyboard bounds changed.
    void NotifyKeyboardBoundsChanging(const gfx::Rect& new_bounds);

    // Management of the observer list.
    virtual void AddObserver(KeyboardControllerObserver* observer);
    virtual void RemoveObserver(KeyboardControllerObserver* observer);

    KeyboardUI* ui() { return ui_.get(); }

    void set_lock_keyboard(bool lock) { lock_keyboard_ = lock; }

    KeyboardMode keyboard_mode() const { return keyboard_mode_; }

    void SetKeyboardMode(KeyboardMode mode);

    // Force the keyboard to show up if not showing and lock the keyboard if
    // |lock| is true.
    void ShowKeyboard(bool lock);

    // Sets the active keyboard controller. KeyboardController takes ownership of
    // the instance. Calling ResetIntance with a new instance destroys the
    // previous one. May be called with NULL to clear the instance.
    static void ResetInstance(KeyboardController* controller);

    // Retrieve the active keyboard controller.
    static KeyboardController* GetInstance();

    // Returns true if keyboard is currently visible.
    bool keyboard_visible() { return keyboard_visible_; }

    bool show_on_resize() { return show_on_resize_; }

    // Returns the current keyboard bounds. An empty rectangle will get returned
    // when the keyboard is not shown or in FLOATING mode.
    const gfx::Rect& current_keyboard_bounds()
    {
        return current_keyboard_bounds_;
    }

private:
    // For access to Observer methods for simulation.
    friend class KeyboardControllerTest;

    // aura::WindowObserver overrides
    void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
    void OnWindowAddedToRootWindow(aura::Window* window) override;
    void OnWindowRemovingFromRootWindow(aura::Window* window,
        aura::Window* new_root) override;
    void OnWindowBoundsChanged(aura::Window* window,
        const gfx::Rect& old_bounds,
        const gfx::Rect& new_bounds) override;

    // InputMethodObserver overrides
    void OnTextInputTypeChanged(const ui::TextInputClient* client) override { }
    void OnFocus() override { }
    void OnBlur() override { }
    void OnCaretBoundsChanged(const ui::TextInputClient* client) override { }
    void OnTextInputStateChanged(const ui::TextInputClient* client) override;
    void OnInputMethodDestroyed(const ui::InputMethod* input_method) override;
    void OnShowImeIfNeeded() override;

    // Show virtual keyboard immediately with animation.
    void ShowKeyboardInternal();

    // Returns true if keyboard is scheduled to hide.
    bool WillHideKeyboard() const;

    // Called when show and hide animation finished successfully. If the animation
    // is aborted, it won't be called.
    void ShowAnimationFinished();
    void HideAnimationFinished();

    scoped_ptr<KeyboardUI> ui_;
    scoped_ptr<aura::Window> container_;
    // CallbackAnimationObserver should destructed before container_ because it
    // uses container_'s animator.
    scoped_ptr<CallbackAnimationObserver> animation_observer_;

    ui::InputMethod* input_method_;
    bool keyboard_visible_;
    bool show_on_resize_;
    bool lock_keyboard_;
    KeyboardMode keyboard_mode_;
    ui::TextInputType type_;

    base::ObserverList<KeyboardControllerObserver> observer_list_;

    // The currently used keyboard position.
    gfx::Rect current_keyboard_bounds_;

    static KeyboardController* instance_;

    base::WeakPtrFactory<KeyboardController> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(KeyboardController);
};

} // namespace keyboard

#endif // UI_KEYBOARD_KEYBOARD_CONTROLLER_H_
